Certain abnormalities of the knee including subluxation of the patella, chrondromalacia, patella tendonitis, and Osgood-Schlatter's disease effectively may be treated by use of a knee brace specifically designed to stabilize the knee and promote normal patella tracking. The known devices of this type usually consist of a sleeve fitted about the knee and carrying a pair of live rubber "stays" straddling the patella. The sleeve and stays are maintained in position by a series of circumferentially extending straps held in place by suitable fastening elements, e.g. VELCRO material. These prior art braces, however, are characterized by various disadvantages. They must be firmly engaged about the knee to maintain the rubber stays in their proper supporting relation with the patella and, therefore, are frequently uncomfortable to wear especially when complete functionality of the leg's extensor mechanism is desired. Moreover, these prior devices are difficult to adjust for optimum effect and comfort, and different sizes are necessary to fit different subjects.